Method for recovering esters and other volatile components



Jan. 19, 1954 E. R. BEU

METHOD FOR RECOVERING ESTERS AND OTHER VOLATILE COMPONENTS Filed June24. 1950 R l my n NE N ma oA Qowwu, .Se NE. T M055 QMQSQAI I u ,S MOSStwmu, IY

Patented Jan. 19, 1954 aan? METHOD FOR RECOVERING ESTERS AND OTHERVOLATILE COMPONENTS Eric R. Ben, Albion, N. Y.

Application June 24, 1950, Serial No. 170,207

8 Claims.

This invention relates to a method and apparatus for removing esters andother volatile components of flavors and aromas from any solid,semi-solid, liquid, semi-liquid, gas, or other fluid, with moreparticular reference to recovering the natural aroma and flavoring fromorange juice and other fruit and vegetables juices and liquid foods, andit has for its purpose to afford a meth-y od by which the esters andother flavor and aroma components in a fruit juice or liquid food can besuccessfully removed before evaporation or dehydration and thereafteradded to the concentrated product so as to restore substantially theentire volume of flavor and aroma components and thus produce aconcentrate which when added to Water produces a beverage or food thatpossesses substantially the same flavor and aroma characteristics as thejuice in its original and natural state.

The general practice in concentrating orange juice has been to retainabout 10% of the total volume in its natural state and mixsuch 10% withthe concentrate produced from the remain ing 90%, in order to simulatethe flavor and aroma of the original juice, but a large percentage ofthe aroma and flavor components are lost in condensing the water of the90% or large total volume from which the concentrate is formed, and itis a particular purpose of the invention to afford a procedure thatenables removing from the entire volume of juice in the rst instancesubstantially all of the avor and aroma components, these volatilecomponents being contained in a very small Volume of approximatelyone-tenth of 1% of the total volume of juice, so that the remaining99.9% volume of juice can be concentrated withoutV losing orv affectingthe aroma and flavor components, which are recovered from the juicebefore the concentration operation so that they may be added to theconcentrate after the latter is produced, and when combined in properproportions with the concentrate maintainin the `concentratesubstantially the same fresh flavorand aroma as in the f juice in itsnatural state.

The invention also has for an objective to enf able removing aromas,odors, or scents from solids, semi-solids, liquids, semi-liquids,-gases, or other fluids and condensing the esters or other componentsforming the aromas, odors and scents into a concentrate or extract thatcan be ponents of flavors and aromas from a gaseous material that hasbeen previously mixed with said volatile components, taking the place ofthe water, air or other carrier` of such components, and acting toconvey them to suitable condensers in which the esters and other flavorand aroma components are condensed and recovered.

The invention in its general aspect consists in supplying to a liquid,juice, or other substance an excess amount of non-condensable gas whichpicks up the volatile flavor and aroma components, and from which theavor and aroma components are recovered, utilizing for this purpose agas that is inert and non-reactant at temperatures of approximately F.and below, such as nitrogen, or any other inert gas, while maintainingthe liquid or juice and gas at a pressure slightly higher than theequilibrium vapor pressure at the freezing point of the uid undergoingtreatment.

Such gas is mixed with a volume of orange juice or other fruit juice, orliquid, rand the mixed liquid and gas conducted through a continuousevaporator comprising a heater and separator, or through a suitablepacked tower or other desorption unit. The gas acts to remove and carryoff the volatile components of the avor and aroma, which volatilecomponents or vapors from `evap-oration are carried by the nitrogen orother gas at a temperature of approximately +327F. or above to a suraoecondenser that is chilled by a refrigerant having a tem' perature ofapproximately +32 F. to 40 F. and in which the larger part of the Waterand relatively lower boiling fractions are removed and carried ocontinuously while the gas with the flavor and aroma components areconducted thence to a second condenser where they are subjected to arefrigerant at a very low temperature of approximately from +32 to 459F., causing the flavor and aroma esters and other components tocrystallize and adhere to the Wall of the condenser in the form of snow.

This snow or crystal formation is removed in any suitable fashion as byan electrical vibrator, causing the crystals to fall to a warmingchamber at the bottom of the condenser and beneath a suitable baiiielocated under the gas outlet, the aroma and flavor component crystalsbeing liqueiled inthe warming chamber and drawn oi continuously formixing with the concentrate that is produced by any conventionalmethods, while the nitrogen or other gas is conducted from the lastmentioned condenser through a suitable source of vacuum and returned ina continuous circuit, first in liquid form to chill the last mentionedcondenser and then in gaseous form to be mixed with the incoming juiceorliquid. The flavor and aroma recovery process may be carried outseparately from the concentration of such substances, or in conjunctionwith the concentration process if preferred, and the nitrogen may berecirculated, or a fresh supply of liquid nitrogen introduced for eachcycle, if desirable.

To these and other ends, the invention consists in the method andapparatus that will appear more clearly from the following descriptionwhen read in conjunction with the accompanying drawing, the novelfeatures being pointed out in the claims following the specification.

The drawing is a diagrammatic view of an apparatus illustrative of onemethod of carryout the process forming part of the subject matter of theinvention.

The method forming part of the invention may be performed with varioustypes and arrangements oi' apparatus, and in order to illustrate onepractical embodiment, there is shown a structure including an inlet pipel for orange or other fruit juice or liquid, controlled by valve 2, andcommunicating with a mixing chamber 3, into which leads a pipe l forconducting nitrogen gas at a temperature of 40 F. or above, a suitableheat-exchanger 5 being employed for such purpose, the gas being thusmixed with the fruit juice or liquid in the mixing chamber 3.

Satisfactory results are obtainable with nitrogen gas although any gasmay be used that is inert or non-reactant at low temperatures withorange juice or other fruit or vegetable juices or liquids, such ashelium, argon, xenon, Krypton, or carbon dioxide, or any mixtures oithese, or air or other gas which when mixed function to remove theesters and other 'flavor and aroma components from the liquid bydesorption and carry them to the point where the esters and other iiavorand aroma components are condensed out of the gas at low temperaturesinto the form of crystals or snow and recovered in liquid form.

After the gas and liquid are brought together, the mixture is conductedthrough a pipe 5 to a suitable heat-exchanger in the form of a downilowheater the mixture of nitrogen gas and liquid being carried through thepipes 52 of the heater and the stripped liquid or juice is conductedaway from the heater through a pipe 9 by a suitable ilexible impellerpseudo-positive action pump, such as a Jabsco pump, as indicated at i l.i2 designates a valve for controlling the flow through pipe 9, and steamis introduced into the chamber surrounding the pipes 8 through an inleti3, the steam condensate being carried ou through pipe lll by acentrifugal pump or other suitable means indicated at I5.

Steam is introduced through inlet I3 at a temperature of +32@ F. orabove while the juice or aqueous liquid enters the heater at atemperature between 0 F. and +70 and the inert gas at a temperaturebetween +32" F. and -459 F. depending on the particular gas used. Afterpassing through the heat-exchanger just described rom which the majorpart of the juice or liquid is stripped from the flavor and aromacomponents, the gas together with the avor and aroma components travelthrough the pipe IS controlled by valve l-to a separator i3, movingupwardly in the latter while t e stripped liquid or juice is carrieddoiinvvardly through pipe it controlled by valve 2| to the previouslymentioned discharge pipe 9 leading from the heater '1, substantially allof the stripped juice being carried off in this fashion through pipes 9and l!! by pump Il, while the nitrogen gas or other gaseous carriermoves upwardly through pipe 22 ang to a condenser which will bedescribed presen y.

In actual operation, it has been found that the nitrogen or othernon-ccndensable gas removes by desorption approximately .1% of the totalvolume of orange juice or other liquid passing through the heater andseparator just described, the esters and other flavor and aromacomponente being contained in this relatively small proportion of thetotal volume of juice, while approximately 99.9% of the total volume ofjuice is stripped and carried off through the pipes S and I9, thestripped juice or liquid being concentrated to any extent desired byconventional methods either into liquid or powdered concentrate form,and the flavor and aroma components which are recovered from therelatively small volume of liquid in the manner that will be describedpresently can then be added to the stripped juice to produce a nalconcentrate which, when water is added at the time of using, willreproduce the flavor and aroma characteristics of the original ornatural juice.

Instead of the heater and separator just described, the flavor and aromacomponents may be removed from the juice or liquid by any otherdesorption method or apparatus suitable for the purpose, such forinstance as a packed tower in which the juice or liquid andnon-.condensable gas travel in opposite directions through a mass ofceramic or other suitable non-reacting packing material, the nitrogengas acting to remove the volatile esters and other flavor and aromacomponents from the fruit juice or liquid and carry them on to therecovery'point in the manner thatwill new be described.

The mixture4 of nitrogen gas and iiavor and aroma components is carriedthrough the separator i8 andrthe remainder of the system to be describedby a suitable pump or other source ci vacuum which maintains a pressurethroughout the system slightly higher than the equilibrium vaporpressure at the freezing point oi the fluid undergoing treatment, and inorder to effect the desired condensation of the flavor and aromacomponents, the gas is then conducted through the pipe 22to a,condenser, indicated generally at 23 and Aincluding an inlet chamber24at the top provided witha vertical baille 25 separating the inletchamber 24 from an outlet chamber 26.

2'! designates a multiplicity of inlet passages or conductors inthecondenser 23 communicatingV with the inlet chamber 24 and extendingdownwardly to a chamber 28 at the bottom of the condenser, while 2,9designates a single outlet passage leading from the bottom chamber 2Eupwardly to. the outlet chamber 2E. 3i designates a pipe extendingdownwardly from the bottom chamber 28 and controlled vby a pump 3?. tocarry off continuously such water and other relatively low boilingfractions as may be condensed inthe chamber 23.

This condenser 23 is not necessarily restricted to any specific numberof inlet and outlet passages or relationship between them, the mainobjective being to-aiford a relatively large condensing surface againstwhich the incoming gas strikes and-a relatively small condensationsurface in the passage through which the outgoing gas travels fromthecondenser, this arangement affording Ymaximum efficiency andV maximumcondensing action.

`Surrounding the conducting passages 21 and 29 is a jacket affording achamber for a refrigerant such as brine which enters through the pipe33, controlled by valve 34, and is carried off at the top of theVrefrigerant chamber through pipe for a purpose that willpresentlyappear, and the refrigerant is conducted to the condenser at atemperature of between F. and +32 F., while the nitrogen gas and flavorand aroma components are maintained at a temperature of between -40 F.and +32 F. while in the condenser, Substantially all remaining water orliquid or other relatively lower boiling fractions are removed from thegaseous carrier by the condenser 23, leaving only the avor and aromacomponents to be conducted to a second condenser where they are removedfrom the gas in the manner that will now be described.

To eiect this, the pipe 36 leading from the outlet chamber 26 ofcondenser 23 connects with the top of a second condenser or trap 31,while 36 designates a gas outlet pipe leading from near the bottom ofcondenser 31 upwardlyl and outwardly from the condenser to a suitableturbocompressor or other pump 39 which maintains the required lowpressure throughout the system and compresses the nitrogen to a higherpressure than that existing in the system. The nitrogen -r gas at suchhigher pressure then passes through a suitable condenser 4l whichliquees the compressed nitrogen and thence through expansion valve 42which controls the degree of refrigeration in the condenser trap. Thecondenser 4l may be cooled by gaseous nitrogen which passes through thepipe 43 from chamber 44 surrounding the condenser, and which then passesfrom condenser 4l to the inlet pipe 4 to the mixing chamber 3 where thejuice is introduced. The liquid nitrogen travels from expansion valve 42to the chamber 44 surrounding the condenser 31 to effect the necessarychilling.

The liquid nitrogen which flows through the jacket or chamber 44 is at atemperature of 344 F. and above, causing the esters and other volatileflavor and aroma components which are maintained at about the sametemperature to crystallize on the inside of the wall of the condenser inthe form of a light snowlike material while the nitrogen gas is carried,olf through the pipe 43 as already described.

V45 designates an electric or other suitable vibrator attached to thewall of the condenser 31 and operating to loosen the crystals or snow asthey form on the wall of the condenser, and permitjthem to fall bygravity downwardly and around the' edges of a b'afe 46 locatedimmediate- 1yunder the lower end of gas outlet pipe 38, and into awarming chamber 41 whichis surrounded vbya jacket or chamber 48, towhich is connected the aforementioned pipe 35 leading fromtherefrigerant chamber of condenser 23.

Thus the refrigerant or brine passing through pipe 35maintains the wallsof the warming chamber 41 at a temperatureof approximately-f+32 F.,causing the snow or crystals constituting the ilavor and aromacomponents to liquefy inthe warming chamber 41, whence they arecontinuously conducted olf through a pipe 49 by a pump 5I of the Jabscotype already described while 52 designates a controlling valve in pipe49.

53 designates a pipe communicating with the lower part of the jacket orchamber 44 and controlled by a pump 54 that is manually or autotrap inany suitable 6. matically operable to remove such excess oxygen,nitrogen and other liquids as may accumulate in the system, while 55designates a pipe controlled byv a pump 56, which is operated manuallyor automatically to remove such excess gases as may accumulate in thesystem. If additional liquid Vnitrogen is required, it can be suppliedfrom any suitable source through the pipe 53 and pump 54, which isreversible in operation. 51 is an outlet pipe for conducting refrigerantfrom the warming chamber 41.

The operation of the apparatus briefly is as follows: Fruit andVegetable juice or other liquid from which it is desirable to recoverflavor and aroma components is introduced through the pipe l into amixing chamber 3 where it is combined with nitrogen or other gas, andthe mixture conducted to the heat-exchanger or downflow heater 1 andseparator I8. Approximately 99.9% of the total volume of juice or liquidis stripped in evaporator 1 and separator I8 and carried off, whiletheremaining .1 of the total volume in the form of a small amount ofwater and volatile flavor and aroma components are carried on by thenitrogen or other gas to condenser 23 from which most of the water andrelatively lower boiling fractions are removed.

The remaining esters and other volatile ilavor and aroma components arecarried by the nitrogen gas to condenser trap 31 where they aresubjected to very low temperatures which cause the esters and ilavor andaroma components to collect on the wall of the trap in the form of snowor crystals, which are loosened from the wall of the fashion, as by anelectric vibrator, and fall thence downwardly into the warming chamberwhere they are subjected to the action of a warming fluid whichliquefles the crystals. The iiavor and aroma components are drawn offvfrom the warming chamber continuously -to be mixed with the concentratefrom the juice or liquid, from which they have been previouslyseparated.

Thus substantially nothing is removed or lost from the juice but water,and when water is added to the concentrate at the time of use, the juiceor liquid is restored to its original state and the juice possesses thesame fresh flavor and aroma which characterized it in its natural state.The nitrogen or other gas is carried off from condenser trap 31 andliquefied by condenser 4 l, after its pressure is raised by thecompressor 39, and then passes through expansion valve 42 and returns tothe refrigerant chamber 44 around the condenser 31,

vand is thenready for repeating the cycle as described.

The invention has the additional advantage of deaerating the juice orliquid and removing substantially all oxygen, thus increasing thestability of the flavor of the product. The invention is also applicablein the removal of flavor and aroma components from any liquids or fromthev air as in the case of separating aroma components froman atmosphereheavily laden with an aroma that it is desirable to recover, such forinstance .asthe fragrance of gardenas, roses, or other flowers in agreenhouse, room, or chamber, in which case it is possible to introducenitrogen or other gas into such room or chamber and pick up and carryoff the aroma components, which can be condensed and recovered in themanner previously described, and subsequently used by mixing with aconcentrate, extract, or in any other desirable manner.

The force which drives the volatile components into the inert gas streamis the greaterl vapor pressure of the volatile components as comparedwith the vapor pressures of the water' or other liquid or less volatilecomponentsin the' material under treatment. This driving force ismagnified both by low absolute pressure and heat in the heater-typedesorption unit and by low absolute pressure alone-in the packed towerdesorption unit.

While the invention has been describedl withl reference to theparticular construction herein shown and the method described, it is notconned to the exact arrangement, details, or procedure set forth sincethe method and structure are susceptible of changes and modicationswithout departing from the essential features of the invention, and thisapplication is intended to cover such adaptations or modifications asmay come Within the purposes of the improvements and the scope of thefollowing claims.

I claim:

1. The method of continuously recovering` esters and other volatilecomponents of flavors and aromas from a iluid which consists incontinuously mixing with the uid a normally non condensable gas,continuously separating said gas with the volatile flavor and aromacomponents lfrom the mixture while the latter is maintained at asub-atmospheric pressure, contnuously removing said fluid from themixture, continously conducting said gas with the stripped volatiles andcondensable vapor in co-current relationship away from said mixture andremving the condensable vapor therefrom, thence conducting the strippedvolatiles and gas in cocurrent relationship to a point where thevolatiles are separated from the non-condensacle gas in the form ofsolid crystals, and converting said crystals into a fluid.

2. The method of continuously recovering esters and other volatilecomponents of iiavors and aromas from a fluid which consistsincontinuously mixing with the fluid a normally noncondensable gas,continuously separating said gas with the volatile flavor and aromacomponents from the mixture While the latter is maintained at atemperature of not lower than 0 F. and at a sub-atmosphericpressure,continuously removing said uid from the mixture, continuouslyconducting said gas with the stripped volatile:I and condensable vaporin co-current relationship away from said mixture and removing thecondensable vapor therefrom while subjecting the gas and volatiles to atemperature of not higher than 32 F., thence conducting the strippedvola-tiles and gas in co-current relationship to a point where'they arevsubjected to atemperature of below 32 F. andthe volatiles are separatedfrom the non-condensable gas in the form of solid crystals, andconverting said crystals into a fluid. v

3. The method of continuously recovering esters and other volatilecomponents of flavors and aromas from a fruit juice which consists incontinuously mixing with the juice a normally non-oondensable gas,continuously separatingsaid gas with the volatile ilavor and aromacomponents from the mixture While the latter is maintained at atemperature of not lower than 0 F. and at a sub-atmospheric pressure,continuously removing the fruit juice from themixture,rcontinuouslyconducting said gas with the stripped volatiles and condensable vapor incocurrent relationship away from said mixture and removing thecondensable vapor therefrom while-subjecting thel gas and volatiles toa' temperature of not higher than 32 F., thence conducting the strippedvolatilesand gas in co-current relationship to a point where theyare-subjected to a temperature of below 32 F. and the volatiles areseparated from the non-condensable gasin the form of solid crystals, andconverting said crystals into a juice.

4. The method of continuously recovering esters and other volatilecomponents of avors and aromas from orange juice which consists incontinuously mixing with the orange juice a normally non-condensablegas, continuously separatingsaid gas with the volatile avor and aromacomponents from the mixture while the latter is maintained at atemperature of not lower than 0 F. and at a sub-atmospheric pressure,continuously removing the orange juice from the mixture, continuouslyconducting saidgasv with the stripped volatiles and condensable vapor inco-current relationship away from said mixture and removing thecondensable vapor therefrom while subjecting the gas and volatiles to atemperature of not higher than 32 F., thence conducting the strippedvolatiles'and gas in co-current relationship to al point where they aresubjected to a temperature of below 32 F. and the volatiies areseparated from the non-condensable gas in the formof solid crystals, andconverting said crystals into juice.

5. The product produced bythe method of claim l.

6. The product produced by the method of claim 2.

7. The product produced `by the method of claimr 3.

8. The productl produced by the method of claim 4.

ERIC R. BEU.

ReferencesCited in the le of this patent UNITED STATES PATENTS NumberName Date 12231359V Etaix Dec. 25, 1917 1,367,726" Trigg Feb; 8, 19212,018,049 Allen Oct. 22, 1935 2,145,395 HOrvath Jari. 31, 1939 2,306,061Johnson Dec. 22, 1942 2,423,746 Zahm July 8, '1947 2,510,138 Pulley etal. June 6, 1950 2,512,513 Zahm June 20, 1950 2,513,813 Mllelvlle July4, 1950 FOREIGN PATENTS Number Country Date 246,454 Great Britain f 1926

1. THE METHOD OF CONTINUOUSLY RECOVERING ESTERS AND OTHER VOLATILECOMPONENTS OF FLAVORS AND AROMAS FROM A FLUID WHICH CONSISTS INCONTINUOUSLY MIXING WITH THE FLUID A NORMALLY NONCONDENSABLE GAS,CONTINUOUSLY SEPARATING SAID GAS WITH THE VOLATILE FLAVOR AND AROMACOMPONENTS FROM THE MIXTURE WHILE THE LATTER IS MAINTAINED AT ASUB-ATMOSPHERIC PRESSURE, CONTINUOUSLY REMOVING SAID FLUID FROM THEMIXTURE, CONTINUOUSLY CONDUCTING SAID GAS WITH THE STRIPPED VOLATILESAND CONDENSABLE VAPOR IN CO-CURRENT RELATIONSHIP AWAY FROM SAID MIXTUREAND REMOVING THE CONDENSABLE VAPOR THEREFROM, THENCE CONDUCTING THESTRIPPED VOLATILES AND GAS IN COCURRENT RELATIONSHIP TO A POINT WHERETHE VOLATILES ARE SEPARATED FROM THE NON-CONDENSABLE GAS IN THE FORM OFSOLID CRYSTALS, AND CONVERTING SAID CRYSTALS INTO A FLUID.